The present invention relates to a radiographic image reading method employing a radiographic image conversion panel such as an accumulative phosphor (stimulating phosphor plate) and to a radiographic image reading apparatus.
When radioactive rays (X-rays, xcex1-rays, beta rays, gamma rays and ultraviolet rays) are applied to a phosphor of a certain type, a part of the radiation energy is accumulated in the phosphor. It has been known that when an excitation light such as a visible light is applied to a phosphor, the phosphor emits light through stimulation in accordance with energy accumulated in the phosphor. A phosphor indicating this property is called an accumulative phosphor or a stimulative phosphor.
By utilizing this stimulative phosphor, it is possible to record temporarily radiographic image information of the human body on an accumulative phosphor (a radiographic image conversion panel) provided on a sheet, then to scan the radiographic image conversion panel with an excitation light such as a laser beam so that a stimulated emission light may be generated, and to read photoelectrically the stimulated emission light thus generated to obtain image signals.
Incidentally, the radiographic image conversion panel is not controlled strictly in terms of its sensitivity. Namely, even in the case of radiographic image conversion panels under the same brand, they delicately differ in terms of sensitivity, depending on the date of production.
In the case of an apparatus wherein a radiographic image conversion panel is housed in a cassette for radiographing and reading, in particular, it can happen that new and old radiographic image conversion panels each having different sensitivity are housed in the same cassette.
In this case, a signal value of the radiographic image is used by a radiographer to judge whether a level of the dose of irradiation is high or low. Therefore, when the signal value varies depending on the radiographic image conversion panel, it is impossible to judge or control the level of the dose of irradiation.
Further, when radiographing for plural radiographic images under the condition that radiographic image conversion panels each having different sensitivity are present as a mixture, radiographic images each having a different signal value are obtained, although the same subject is radiographed under the same dose of X-rays. Therefore, it is difficult to make a correct diagnosis.
The invention has been achieved to solve the aforesaid problem, and its object is to realize a radiographic image reading method and a radiographic image reading apparatus which make it possible to obtain the constant signal value for the constant dose of X-rays, independently of sensitivity of the radiographic image-conversion panel.
Methods and structures for solving the aforesaid problems will be explained as follows.
(1) A radiographic image reading method of reading a radiographic image on a radiographic image conversion panel and for obtaining radiographic image information; comprising steps of:
reading panel discriminating information corresponding to the radiographic image conversion panel, thereby obtaining information regarding the radiographic image conversion panel; and
applying image processing for the radiographic image information based on the information regarding the radiographic image conversion panel.
(2) A radiographic image reading apparatus, comprising:
image reading means for reading a radiographic image on a radiographic image conversion panel and for obtaining radiographic image information;
panel discriminating information reading means for reading panel discriminating information corresponding to the radiographic image conversion panel and for obtaining information regarding the radiographic image conversion panel;
image processing means for applying image processing for the radiographic image information; and
control means for controlling the image processing means so as to apply the image processing for the radiographic image information on the basis of the information regarding the radiographic image conversion panel.
With the invention described in Items (1) and (2), since image processing can be applied to radiographic image information in accordance with a radiographic image conversion panel, the radiographic image information more suitable for diagnosis can be obtained.
Further, since the image processing conformable to the characteristics of the radiographic image conversion panel, such as the sensitivity of the radiographic image conversion panel can be conducted by obtaining information regarding the manufacturing date of the radiographic image conversion panel, the version of the radiographic image conversion panel, fading information or the material constituting the radiographic image conversion panel as the information regarding the radiographic image conversion panel, the radiographic image information more suitable for diagnosis can be obtained.
(3) A radiographic image reading method of reading a radiographic image on a radiographic image conversion panel and for obtaining radiographic image information; comprising steps of:
reading panel discriminating information corresponding to the radiographic image conversion panel, thereby obtaining information regarding the radiographic image conversion panel; and
warning information regarding time limit for use of the radiographic image conversion panel.
(4) A radiographic image reading apparatus, comprising:
image reading means for reading a radiographic image on a radiographic image conversion panel and for obtaining radiographic image information;
discriminating information reading means for reading panel discriminating information corresponding to the radiographic image conversion panel and for obtaining information regarding the radiographic image conversion panel; and
warning means for warning information regarding time limit for use of the radiographic image conversion panel.
With the invention described in Items (3) and (4), the image deterioration caused by the use of the radiographic image conversion panel whose time limit for use is terminated can be refrained, the radiographic image information more suitable for diagnosis can be obtained.
(5) A radiographic image conversion panel for storing a radiographic image, comprising:
a panel discriminating section provided with panel discriminating information regarding the manufacturing date of the radiographic image conversion panel, the version of the radiographic image conversion panel, fading information or the material constituting the radiographic image conversion panel.
(6) A cassette in which a radiographic image conversion panel for storing a radiographic image is accommodated, comprising:
an accommodating section in which the radiographic image conversion panel for storing a radiographic image is accommodated; and
a panel discriminating section provided with panel discriminating information regarding the manufacturing date of the radiographic image conversion panel, the version of the radiographic image conversion panel, fading information or the material constituting the radiographic image conversion panel.
With the invention described in Items (5) and (6), since image processing can be applied in accordance with a radiographic image conversion panel, the radiographic image information more suitable for diagnosis can be obtained.
(7) A radiographic image reading method, comprising, steps of:
reading panel discriminating information corresponding to the radiographic image conversion panel, thereby obtaining information regarding the radiographic image conversion panel;
obtaining a reading condition to read radiographic image information stored in the radiographic image conversion panel on the basis of the information regarding the radiographic image conversion panel; and
reading the radiographic image-information stored in the radiographic image conversion panel on the basis of the reading condition.
(8) A radiographic image reading apparatus, comprising:
image reading means for reading a radiographic image on a radiographic image conversion panel and for obtaining radiographic image information;
panel discriminating information reading means for reading panel discriminating information corresponding to the radiographic image conversion panel and for obtaining information regarding the radiographic image conversion panel; and
reading condition determining means for obtaining a reading condition to read radiographic image information stored in the radiographic image conversion panel on the basis of the information regarding the radiographic image conversion panel.
With the invention described in Items (7) and (8), since an image on a radiographic image conversion panel can be read on the condition corresponding to the radiographic image conversion panel, the radiographic image information more suitable for diagnosis can be obtained.
(9) A radiographic image reading method of reading a radiographic image on a radiographic image conversion panel and for obtaining radiographic image information; comprising steps of:
reading panel discriminating information corresponding to the radiographic image conversion panel, thereby obtaining information regarding the radiographic image conversion panel; and
eliminating a remaining image on the radiographic image conversion panel on the basis of the information regarding the radiographic image conversion panel.
(10) A radiographic image reading apparatus, comprising:
image reading means for reading a radiographic image on a radiographic image conversion panel and for obtaining radiographic image information;
panel discriminating information reading means for reading panel discriminating information corresponding to the radiographic image conversion panel and for obtaining information regarding the radiographic image conversion panel; and
eliminating means for eliminating a remaining image on the radiographic image conversion panel on the basis of the information regarding the radiographic image conversion panel.
With the invention described in Items (9) and (10), since noise remaining after an image on the radiographic image conversion panel is read can be eliminated on the eliminating condition corresponding to the radiographic image conversion panel, the radiographic image information on the radiographic image conversion panel photographed after the eliminating operation can be obtained as an image more suitable for diagnosis.